Salak

Configuration Loader for Production in Haskell.

How to use this library

| This library default a standard configuration load process. It can load properties from CommandLine, Environment, `JSON value` and Yaml files. They all load to the same format SourcePack. Earler property source has higher order to load property. For example:

CommandLine:  --package.a.enabled=true
Environment: PACKAGE_A_ENABLED: false

lookup "package.a.enabled" properties => Just True

CommandLine has higher order then Environment, for the former load properties earler then later.

Usage:

data Config = Config
  { name :: Text
  , dir  :: Maybe Text
  , ext  :: Int
  } deriving (Eq, Show)

instance FromProp Config where
  fromProp = Config
    <$> "user"
    <*> "pwd"
    <*> "ext" .?= 1

main = do
  c :: Config <- defaultLoadSalak def $ require ""
  print c

λ> c
Config {name = "daniel", dir = Nothing, ext = 1}

Salak

defaultLoadSalak :: MonadIO m => PropConfig -> ReaderT SourcePack m a -> m a

Default load salak. All these configuration sources has orders, from highest order to lowest order:

1. CommandLine
2. Environment
3. Specified Yaml file(file in `configDirKey`)
4. Yaml file in current directory
5. Yaml file in home directory

loadSalak

Arguments

:: Monad m

=> ReaderT SourcePack m a

Fetch properties monad.

-> SourcePackT m ()

Load properties monad.

-> m a

Load salak SourcePack and fetch properties.

data PropConfig

Prop load configuration

Constructors

PropConfig

Fields

• configName :: Maybe String

  Config name

• configDirKey :: Text

  Specify config dir

• searchCurrent :: Bool

  Search current directory, default true

• searchHome :: Bool

  Search home directory, default false.

• commandLine :: ParseCommandLine

  How to parse commandline

Instances

Default PropConfig

Defined in Salak

Methods

def :: PropConfig

Static Load

class Monad m => HasSourcePack m where

Methods

askSourcePack :: m SourcePack

Instances

Monad m => HasSourcePack (StateT SourcePack m)

Defined in Salak

Methods

askSourcePack :: StateT SourcePack m SourcePack

Monad m => HasSourcePack (ReaderT SourcePack m)

Defined in Salak

Methods

askSourcePack :: ReaderT SourcePack m SourcePack

fetch

Arguments

:: (HasSourcePack m, FromProp a)

=> Text

Properties key

-> m (Either String a)

Try fetch properties from SourcePack

require

Arguments

:: (HasSourcePack m, FromProp a)

=> Text

Properties key

-> m a

Fetch properties from SourcePack, or throw fail

Dynamic Load

data ReloadableSourcePack

Reloadable SourcePack

type ReloadableSourcePackT = StateT ReloadableSourcePack

data ReloadResult

Constructors

ReloadResult

Fields

• isError :: Bool
• msg :: [String]

Instances

Eq ReloadResult

Defined in Salak.Dynamic

Methods

(==) :: ReloadResult -> ReloadResult -> Bool

(/=) :: ReloadResult -> ReloadResult -> Bool

Show ReloadResult

Defined in Salak.Dynamic

Methods

showsPrec :: Int -> ReloadResult -> ShowS

show :: ReloadResult -> String

showList :: [ReloadResult] -> ShowS

reloadable :: (MonadIO m, HasSourcePack m) => ReloadableSourcePackT m a -> m a

Lift to reloadable environment for dynamic properties.

fetchD

Arguments

:: (MonadIO m, FromProp a)

=> Text

Properties key

-> ReloadableSourcePackT m (Either String (IO a))

Try fetch dynamic properties from SourcePack

requireD

Arguments

:: (MonadIO m, FromProp a)

=> Text

Properties key

-> ReloadableSourcePackT m (IO a)

Fetch dynamic properties from SourcePack, or throw fail

Prop Parser

type Prop = PropT PResult

class FromProp a where

Minimal complete definition

Nothing

Methods

fromProp :: Prop a

fromProp :: (Generic a, GFromProp (Rep a)) => Prop a

Instances

FromProp Bool

Defined in Salak.Prop

Methods

fromProp :: Prop Bool

FromProp Double

Defined in Salak.Prop

Methods

fromProp :: Prop Double

FromProp Float

Defined in Salak.Prop

Methods

fromProp :: Prop Float

FromProp Int

Defined in Salak.Prop

Methods

fromProp :: Prop Int

FromProp Int8

Defined in Salak.Prop

Methods

fromProp :: Prop Int8

FromProp Int16

Defined in Salak.Prop

Methods

fromProp :: Prop Int16

FromProp Int32

Defined in Salak.Prop

Methods

fromProp :: Prop Int32

FromProp Int64

Defined in Salak.Prop

Methods

fromProp :: Prop Int64

FromProp Word

Defined in Salak.Prop

Methods

fromProp :: Prop Word

FromProp Word8

Defined in Salak.Prop

Methods

fromProp :: Prop Word8

FromProp Word16

Defined in Salak.Prop

Methods

fromProp :: Prop Word16

FromProp Word32

Defined in Salak.Prop

Methods

fromProp :: Prop Word32

FromProp Word64

Defined in Salak.Prop

Methods

fromProp :: Prop Word64

FromEnumProp a => FromProp a

Defined in Salak.Prop

Methods

fromProp :: Prop a

FromProp Scientific

Defined in Salak.Prop

Methods

fromProp :: Prop Scientific

FromProp Text

Defined in Salak.Prop

Methods

fromProp :: Prop Text

FromProp Text

Defined in Salak.Prop

Methods

fromProp :: Prop Text

FromProp String

Defined in Salak.Prop

Methods

fromProp :: Prop String

FromProp a => FromProp [a]

Defined in Salak.Prop

Methods

fromProp :: Prop [a]

FromProp a => FromProp (Maybe a)

Defined in Salak.Prop

Methods

fromProp :: Prop (Maybe a)

class FromEnumProp a where

Methods

fromEnumProp :: Text -> Either String a

(.?=) :: Alternative f => f a -> a -> f a infixl 5

Optional value.

(.?:) :: (Alternative f, Default b) => f a -> (b -> a) -> f a infixl 5

Default value.

SourcePack

data SourcePack

Instances

Show SourcePack

Defined in Salak.Types

Methods

showsPrec :: Int -> SourcePack -> ShowS

show :: SourcePack -> String

showList :: [SourcePack] -> ShowS

MonadReader SourcePack Prop

Defined in Salak.Prop

Methods

ask :: Prop SourcePack

local :: (SourcePack -> SourcePack) -> Prop a -> Prop a

reader :: (SourcePack -> a) -> Prop a

Monad m => HasSourcePack (StateT SourcePack m)

Defined in Salak

Methods

askSourcePack :: StateT SourcePack m SourcePack

Monad m => HasSourcePack (ReaderT SourcePack m)

Defined in Salak

Methods

askSourcePack :: ReaderT SourcePack m SourcePack

type SourcePackT = StateT SourcePack

loadYaml :: MonadIO m => FilePath -> SourcePackT m ()

loadCommandLine :: MonadIO m => ParseCommandLine -> SourcePackT m ()

loadEnv :: MonadIO m => SourcePackT m ()

loadMock :: Monad m => [(Text, Text)] -> SourcePackT m ()

defaultParseCommandLine :: ParseCommandLine

type ParseCommandLine = [String] -> IO [(Text, Priority -> Value)]

type Priority = Int

data Value

Constructors

VStr Priority !Text

VNum Priority !Scientific

VBool Priority !Bool

Instances

Eq Value

Defined in Salak.Types

Methods

(==) :: Value -> Value -> Bool

(/=) :: Value -> Value -> Bool

Ord Value

Defined in Salak.Types

Methods

compare :: Value -> Value -> Ordering

(<) :: Value -> Value -> Bool

(<=) :: Value -> Value -> Bool

(>) :: Value -> Value -> Bool

(>=) :: Value -> Value -> Bool

max :: Value -> Value -> Value

min :: Value -> Value -> Value

Show Value

Defined in Salak.Types

Methods

showsPrec :: Int -> Value -> ShowS

show :: Value -> String

showList :: [Value] -> ShowS